Conventionally, a patient's overall risk of coronary heart disease (CHD) and/or coronary artery disease (CAD) has been assessed based on measurements of cholesterol content of a patient's low density lipoproteins (LDL) and high density lipoproteins (HDL) (LDL-C, HDL-C) rather than the numbers of LDL and HDL particles. LDL-C and HDL-C are used to assess a patient's CHD risk and treatment decisions may be made to reduce the “bad” cholesterol (LDL-C) and/or increase the “good” cholesterol (HDL-C).
A “C-reactive protein” (CRP) test is a blood test that measures the amount of CRP protein in a blood sample. C-reactive protein is thought to measure general levels of inflammation in a patient's body. One type of CRP test, termed a high-sensitivity CRP test (hs-CRP), may be performed to find out if a person has an increased risk of having a heart attack.
NMR spectroscopy has been used to concurrently measure very low density lipoprotein (VLDL), LDL and HDL as VLDL, LDL and HDL particle subclasses from in vitro blood plasma or serum samples. See, U.S. Pat. Nos. 4,933,844 and 6,617,167, the contents of which are hereby incorporated by reference as if recited in full herein. Generally stated, to evaluate the lipoproteins in a blood plasma and/or serum sample, the amplitudes of a plurality of NMR spectroscopy derived signals within a chemical shift region of NMR spectra are derived by deconvolution of the composite methyl signal envelope to yield subclass concentrations. The subclasses are represented by many (typically over 60) discrete contributing subclass signals associated with NMR frequency and lipoprotein diameter. The NMR evaluations can interrogate the NMR signals to produce concentrations of different subpopulations, typically seventy-three discrete subpopulations, 27 for very low density lipoproteins (VLDL), 20 for LDL and 26 for HDL. These sub-populations can be further characterized as associated with a particular size range within the VLDL, LDL or HDL subclasses.
In the past, an “advanced” lipoprotein test panel, such as the LIPOPROFILE® lipoprotein test, available from LipoScience, Raleigh, N.C., has typically included a total high density lipoprotein particle (HDL-P) measurement (e.g., HDL-P number) that sums the concentration of all the HDL subclasses and a total low density lipoprotein particle (LDL-P) measurement that sums the concentration of all the LDL subclasses (e.g., LDL-P number). The LDL-P and HDL-P numbers represent the concentration of those respective particles in concentration units such as nmol/L.
Inflammation can be associated with many different disease states including, but not limited to, CHD. It is also believed that inflammation may modulate HDL functionality. See, e.g., Fogelman, When Good Cholesterol Goes Bad, Nature Medicine, 2004. Carbohydrate components of glycoproteins can perform biological functions in protein sorting, immune and receptor recognition, inflammation and other cellular processes. There can also be variations in structure and differing degrees of glycosylation. See, Gates et al., Glycoprotein Analysis Manual, Overview, 1st edition, 2004, Sigma Aldrich, www.sigmaaldrich.com/img/assests/15402/Glyocprotein. The contents of the above referenced documents are hereby incorporated by reference as if recited in full herein.
In the past, life insurance companies have considered various information regarding a prospective customer to identify whether to insure a person and at what price. One input used by some companies to predict a risk of all cause death for such analysis is a ratio of total cholesterol to HDL-C. However, it is believed that this is a relatively poor predictor of all-cause death.